Comprehensive brain and spinal cord MRI may identify acute clinical events in patients of MS: JAMA

Understanding the association between clinically defined relapses and radiological activity in multiple sclerosis (MS) is essential for patient treatment and therapeutic development. A study was done to investigate clinical events identified as relapses but not associated with new T2 lesions or gadolinium-enhanced T1 lesions on brain and spinal cord magnetic resonance imaging (MRI). This multicenter observational cohort study was conducted between January 2015 and June 2023. Data were extracted on June 8, 2023, from the French multiple sclerosis registry. All clinical events reported as relapses in patients with relapsing-remitting multiple sclerosis were included if brain and spinal cord MRI was performed within 12 and 24 months before the event, respectively, and 50 days thereafter with gadolinium injection. Factors associated with ACES were investigated; patients with ACES and RAM were compared regarding Expanded Disability Status Scale (EDSS) course, relapse rate, confirmed disability accrual (CDA), relapse-associated worsening (RAW), progression independent of relapse activity (PIRA), and transition to secondary progressive (SP) MS, and ACES and RAM rates under each disease-modifying therapy (DMT) were estimated.

Results Among 31 885 clinical events, 637 in 608 patients (493 [77.4%] female; mean [SD] age, 35.8 [10.7] years) were included. ACES accounted for 166 (26.1%) events and were more likely in patients receiving highly effective DMTs, those with longer disease duration (odds ratio [OR], 1.04; 95% CI, 1.01-1.07), or those presenting with fatigue (OR, 2.14; 95% CI, 1.15-3.96). ACES were associated with significant EDSS score increases, lower than those found for RAM. Before the index event, patients with ACES experienced significantly higher rates of relapse (relative rate [RR], 1.21; 95% CI, 1.01-1.46), CDA (hazard ratio [HR], 1.54; 95% CI, 1.13-2.11), and RAW (HR, 1.72; 95% CI, 1.20-2.45). Patients with ACES were at significantly greater risk of SP transition (HR, 2.58; 95% CI, 1.02-6.51). Although RAM rate decreased with DMTs according to their expected efficacy, ACES rate was stable across DMTs. The findings in this study introduce the concept of ACES in multiple sclerosis, which accounted for one-fourth of clinical events identified as relapses.

Reference:

Gavoille A, Rollot F, Casey R, et al. Acute Clinical Events Identified as Relapses With Stable Magnetic Resonance Imaging in Multiple Sclerosis. JAMA Neurol. Published online July 01, 2024. doi:10.1001/jamaneurol.2024.1961